يستعد صديقي للرحيل.

Because Arabic often uses verb–subject–object/complement order, especially in straightforward statements.

So:

• يستعد صديقي للرحيل = is preparing my friend to leave literally = my friend is preparing to leave naturally

You could also say:

• صديقي يستعد للرحيل

That order is also correct, but it puts a little more focus on my friend as the topic.

يستعد means he prepares himself, he gets ready, or he is preparing.

In this sentence, a natural English translation is:

• is preparing to leave
• is getting ready to leave

It comes from the verb استعدّ in the past tense, and يستعدّ is the present/imperfect form.

Because Arabic verbs already include the subject information.

يستعد by itself already tells you:

• ya- = third person masculine singular
• so it means he prepares / he is preparing

That is why Arabic does not need a separate subject pronoun like هو unless you want extra emphasis.

صديقي means my friend.

It breaks down like this:

• صديق = friend
• ـي = my

So:

• صديقي = my friend

The ending ـي is a possessive suffix attached directly to the noun.

In Arabic, possession is usually shown by attaching a suffix directly to the noun.

So instead of saying something like friend of me as separate words, Arabic commonly does this:

• كتابي = my book
• بيتي = my house
• صديقي = my friend

This is one of the most common patterns in Arabic.

للرحيل is a prepositional phrase that goes with يستعد.

It is made of:

• لِـ = for / to
• الرحيل = departure / leaving

So literally:

• يستعد للرحيل = he prepares for departure / for leaving

In natural English, that becomes:

• he prepares to leave
• he gets ready to leave

With استعدّ, Arabic very often uses لِـ before what someone is preparing for.

Because Arabic often uses a verbal noun (called a maṣdar) where English uses an infinitive like to leave.

Here:

• الرحيل is a verbal noun meaning departure or leaving

So Arabic says something closer to:

• he prepares for leaving/departure

while English prefers:

• he prepares to leave

This is a very common difference between Arabic and English.

Grammatically, yes, الرحيل is definite because it has الـ.

But you should not always translate that الـ as English the. Arabic and English do not use articles in exactly the same way.

So in this sentence:

• للرحيل does not have to be translated as for the departure
• the most natural English is still to leave or for departure

In other words, the Arabic article is there, but the best English translation may leave the out.

It is written للرحيل, but the pronunciation needs special attention.

A fully vocalized version is:

• لِلرَّحِيلِ

Important points:

1. The first لِ is the preposition li-
2. The second ل belongs to الـ
3. The letter ر is a sun letter, so the l of الـ is not pronounced fully and the r is doubled

So the pronunciation is approximately:

• li-r-raḥīli

You will hear the r strongly doubled.

A careful pronunciation is:

• yas-ta-ʿid-du

Key things to notice:

• the ع is the letter ʿayn, a consonant English does not have
• the final دّ has a shadda, so the d is doubled

So do not pronounce it like a single d. It is more like:

• ...ʿid-du

not just

• ...ʿidu

A fully vocalized version is:

• يَسْتَعِدُّ صَدِيقِي لِلرَّحِيلِ

Here is what is happening:

• يستعدُّ: ends with -u in the normal indicative form
• صديقي: the subject, so it is nominative in function, but the ending is not obvious because of the attached ـي suffix
• للرحيلِ: after the preposition لِـ, so it is genitive and ends with -i

For many learners, the most useful practical point is simply:

• after a preposition like لِـ, the following noun is genitive

Formally, يستعد is in the imperfect form, which often covers both present and near-future meaning depending on context.

So this can mean:

• my friend is preparing to leave
• my friend is getting ready to leave

Depending on context, it may also imply something about the near future, because preparation usually points forward.

Yes, absolutely.

Both are correct:

• يستعد صديقي للرحيل
• صديقي يستعد للرحيل

The difference is mostly about style and focus:

• يستعد صديقي للرحيل = more typically verbal, neutral narrative style
• صديقي يستعد للرحيل = starts with the topic my friend

Both would be understood easily in Modern Standard Arabic.

Yes, it can help vocabulary building.

يستعدّ comes from the root ع د د, which is connected with ideas of preparing and making ready.

The verb is from Form X:

• past: استعدّ
• present: يستعدّ

For learners, the most useful takeaway is:

• when you see يستعدّ, think to get ready / to prepare oneself

You do not need to master all the morphology immediately, but noticing the pattern will help later.